Thanks for sharing. It is not obvious to me why splix would be interfering, but that driver is now quite a bit older than the official drivers so some strange conflict is possible. I suspect it is more likely a change in CUPS that causes any conflict when both drivers are installed, but reverting CUPS is not practical. And there is certainly no need for splix if you are using the Samsung/HP driver.
Removing printer-driver-splix is safe, and hopefully it will help more people resolve the scanner issues.